SOLR-7457: Make DirectoryFactory publishing MBeanInfo extensible.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1676151 13f79535-47bb-0310-9956-ffa450edef68

solr/CHANGES.txt

@@ -267,6 +267,9 @@ Other Changes
 * SOLR-4839: Upgrade Jetty to 9.2.10.v20150310 and restlet-jee to 2.3.0
   (Bill Bell, Timothy Potter, Uwe Schindler, Mark Miller, shalin)
 
+* SOLR-7457: Make DirectoryFactory publishing MBeanInfo extensible.
+  (Mike Drob via Mark Miller)
+
 ==================  5.1.0 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release

solr/core/src/java/org/apache/solr/core/DirectoryFactory.java

@@ -19,9 +19,9 @@ package org.apache.solr.core;
 
 import java.io.Closeable;
 import java.io.File;
-import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.nio.file.NoSuchFileException;
+import java.util.Collection;
+import java.util.Collections;
 
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FlushInfo;
@@ -264,4 +264,11 @@ public abstract class DirectoryFactory implements NamedListInitializedPlugin,
     String instanceDir = new File(cd.getInstanceDir()).getAbsolutePath();
     return normalize(SolrResourceLoader.normalizeDir(instanceDir) + cd.getDataDir());
   }
+
+  /**
+   * Optionally allow the DirectoryFactory to request registration of some MBeans.
+   */
+  public Collection<SolrInfoMBean> offerMBeans() {
+    return Collections.emptySet();
+  }
 }

solr/core/src/java/org/apache/solr/core/HdfsDirectoryFactory.java

@@ -20,8 +20,8 @@ package org.apache.solr.core;
 import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.HADOOP_SECURITY_AUTHENTICATION;
 
 import java.io.IOException;
-import java.net.URL;
 import java.net.URLEncoder;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Locale;
 import java.util.concurrent.Callable;
@@ -59,7 +59,7 @@ import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.RemovalListener;
 import com.google.common.cache.RemovalNotification;
 
-public class HdfsDirectoryFactory extends CachingDirectoryFactory implements SolrInfoMBean {
+public class HdfsDirectoryFactory extends CachingDirectoryFactory {
   public static Logger LOG = LoggerFactory
       .getLogger(HdfsDirectoryFactory.class);
   
@@ -438,44 +438,8 @@ public class HdfsDirectoryFactory extends CachingDirectoryFactory implements Sol
     }
   }
 
-  // SolrInfoMBean methods
-
   @Override
-  public String getName() {
-    return getClass().getSimpleName() + "BlockCache";
-  }
-
-  @Override
-  public String getVersion() {
-    return SolrCore.version;
-  }
-
-  @Override
-  public String getDescription() {
-    return "Provides metrics for the HdfsDirectoryFactory BlockCache.";
-  }
-
-  @Override
-  public Category getCategory() {
-    return Category.CACHE;
-  }
-
-  @Override
-  public String getSource() {
-    return null;
-  }
-
-  @Override
-  public URL[] getDocs() {
-    return null;
-  }
-
-  @Override
-  public NamedList<?> getStatistics() {
-    if (metrics == null) {
-      return new NamedList<Object>();
-    }
-
-    return metrics.getStatistics();
+  public Collection<SolrInfoMBean> offerMBeans() {
+    return Arrays.<SolrInfoMBean>asList(MetricsHolder.metrics);
   }
 }

solr/core/src/java/org/apache/solr/core/SolrCore.java

@@ -830,6 +830,17 @@ public final class SolrCore implements SolrInfoMBean, Closeable {
     // from the core.
     resourceLoader.inform(infoRegistry);
 
+    // Allow the directory factory to register MBeans as well
+    for (SolrInfoMBean bean : directoryFactory.offerMBeans()) {
+      log.debug("Registering JMX bean [{}] from directory factory.", bean.getName());
+      // Not worried about concurrency, so no reason to use putIfAbsent
+      if (infoRegistry.containsKey(bean.getName())){
+        log.info("Ignoring JMX bean [{}] due to name conflict.", bean.getName());
+      } else {
+        infoRegistry.put(bean.getName(), bean);
+      }
+    }
+
     bufferUpdatesIfConstructing(coreDescriptor);
     
     // For debugging   

solr/core/src/java/org/apache/solr/store/blockcache/Metrics.java

@@ -17,12 +17,15 @@ package org.apache.solr.store.blockcache;
  * limitations under the License.
  */
 
+import java.net.URL;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
 
 import org.apache.solr.common.util.NamedList;
+import org.apache.solr.common.util.SimpleOrderedMap;
+import org.apache.solr.core.SolrCore;
 import org.apache.solr.core.SolrInfoMBean;
 import org.apache.solr.search.SolrCacheBase;
 
@@ -31,7 +34,7 @@ import org.apache.solr.search.SolrCacheBase;
  *
  * @lucene.experimental
  */
-public class Metrics extends SolrCacheBase {
+public class Metrics extends SolrCacheBase implements SolrInfoMBean {
   
   public static class MethodCall {
     public AtomicLong invokes = new AtomicLong();
@@ -75,7 +78,7 @@ public class Metrics extends SolrCacheBase {
   }
 
   public NamedList<Number> getStatistics() {
-    NamedList<Number> stats = new NamedList<Number>();
+    NamedList<Number> stats = new SimpleOrderedMap<>(21); // room for one method call before growing
     
     long now = System.nanoTime();
     float seconds = (now - previous) / 1000000000.0f;
@@ -120,4 +123,26 @@ public class Metrics extends SolrCacheBase {
   private float getPerSecond(long value, float seconds) {
     return (float) (value / seconds);
   }
+
+  // SolrInfoMBean methods
+
+  @Override
+  public String getName() {
+    return "HdfsBlockCache";
+  }
+
+  @Override
+  public String getDescription() {
+    return "Provides metrics for the HdfsDirectoryFactory BlockCache.";
+  }
+
+  @Override
+  public String getSource() {
+    return null;
+  }
+
+  @Override
+  public URL[] getDocs() {
+    return null;
+  }
 }